PROJECT SUMMARY Diseases of small joints such as arthritis and tendon abnormalities are prevalent, which leads to not only lasting patient suffering but also heavy healthcare cost. Musculoskeletal ultrasound imaging is an invaluable tool for diagnosing these diseases. However, current rigid and planar ultrasound probes have limited contact area with the highly curved irregular surfaces of the small joints, which leads to poor acoustic coupling and limited sonographic window. Also, the rigid probes require experienced professionals to scan the joints back and forth, with different scanning positions and orientations, which is labor-intensive and time-consuming. In addition, this causes anisotropic artifacts in the acquired images and is thus highly operator-dependent. In this project, a thin and soft ultrasound probe is proposed to allow conformal and intimate integration with the small joints for comprehensive, rapid, and artifact-free examinations. The approach is to explore an innovative ?island-bridge? structure that integrates an array of high performance rigid ultrasound transducers with an elastomeric polymer matrix, so mechanical properties of the resulting system will be similar to those of the human skin. Advanced imaging processing algorithm based on phased-array control mechanism will be developed. The acquired images will be high resolution in both axial and lateral dimensions. The final device will be tested on cadaver finger joints, and the collected results will be verified with these from conventional ultrasound probes. The soft ultrasound probes may suggest a transformative technology that holds promise for the next generation of wearable diagnostic devices for the small joints.